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To those of you that have not yet retired since this thread was started, and to those of you that have since retired, thank you. This thread (well, the 1/3 that I read), just answered my questions about 'low ambient outdoor temp controls' on my mini split system in our tiny server room. At least in general terms it did. So thanks for the posts, the humor, and the memories.

Originally posted by lugnut This thread (well, the 1/3 that I read), just answered my questions about 'low ambient outdoor temp controls' on my mini split system in our tiny server room. At least in general terms it did.

Thank God someone finally benefited from this epic saga, although you should have suffered thru the entire f#&*ing 95 pages like the rest of us , now quit posting in it so that it will finally go away once and for all!

Did someone suggest going cheap?

If you want to save money and hassle, get a MovinCool spot cooler. 5 ton unit $10000 and your done. When your lease is up you can take the unit with you, not possible if you pay for an installed system. And if for some reason it breaks, you can swap it out with another unit ( rented or provided ) while your purchased unit is being fixed.

I bought my 12 year old daughter a computer. She has a small, rather dense room that I need to cool. The total watts she has in there now is approx 120, plus the need to cool my gerbil housing unit that I keep in there that has a 2800 btu rating.

I would like to go overkill and be able to cool the 17,000 american girl dolls she has in the closet. My question is, what is the smallest unit I can put in that will hold her over for now, and what is the size unit I should put in to allow for the gowth of my gerbil and her american doll collection?

humidity is not a problem because she never sweats and the gerbils have had their sweat glands surgically removed. The gerbils only operate at 10% of their load during the peak load daytime hours and 90% of their load at night.

I have gotten conflicting signals from the gerbils and quotes anywhere from 3 to 5 ton, two speed and one speed systems. What would you suggest?(I mean about the unit not the gerbils)

I also have an Inergen scream supression system for the gerbils in there, just so you know

"I bought my 12 year old daughter a computer. She has a small, rather dense room that I need to cool. The total watts she has in there now is approx 120, plus the need to cool my gerbil housing unit that I keep in there that has a 2800 btu rating."

Question#1: What brand of computer did you get your daughter?

Question#2: What are the dimensions of your daughter's room?

Question#3: Your existing 120 watts, are they constant or are they modulating wattages?

Question#4: What are the indoor as well as the outdoor cooling requirements of your project?

Question#5: Is the future 2,800 BTU/Hr rating sensible, latent, or sensible/latent in nature?

Amazed

To John Dalton:
I am adding to this thread just to keep you from thinking that no one on the east coast uses precise pressure control to obtain discharge temperature control. The previous line was intended to include discharge temperature control of the condenser and the evaporator. The use of many forms of head pressure (flooded condenser, VFD, water regulating valves on water cooled condensers, P66, and the least preferred on precise commercial/industrial applications, the fan cycling control) to obtain a constant head pressure for operation with-in the "typical" design goal of 105F (water cooled) up to 120F air cooled. Before I'm blasted about all of the variations please take into consideration the word typical and its use in ARI guides for component selection. I'm probably just getting in deeper...LOL
The control of the evaporator discharge temperature is a common practice with CRAC systems of most manufactures (as you know and have stated). The use of Hot Gas Bypass not only prevents freeze-up during a low load condition by maintaining the evap. pressure/temperature above freezing, but used in many applications to raise the evap. temp. to a higher temp. to aid in humidity control (preventing excessive removal) to minimize costs involved in adding humidity. (But thats another story involving reheat, Psych. charts, precise air flow for the load etc..)
The other benefit of Hot Gas Bypass when properly set-up is the prevention of the compressor cycling which results in "off time" and temperature spikes in the discharge air.
Everyone was limited in responding to "Servers" needs due to lack of info.
The installing contractor (in my opinion) let down the HVAC trade by not simply logging the complete system to prove the performance of a system he had contracted to install. In the world of Industrial/Commercial, and Process companies in the Fortune 500, he would not have been paid until he documented the performance he contracted to supply. In most cases of this type (granted on a larger scale) the commisioning of the system would have been specified to be completed by a qualified (AABC) 3rd party.
As it was stated many times, where is the info on the load, the air quantities, the pressures and temperatures, etccc....
I am "Liebert Certified", have set-up many a ED-Pac, Stulz, Data Aire, Trane, etc.. and bottom line is...they were designed using all of the same physics as the Trane unit installed at the beginning of this thread. It merely lacked the proper application of controls, airflow, and set-up ( I know...thats overly simplified). Liebert simply used their "package" of proven components and control, not to mention their marketing skills..lol
I am a "newbie" to this site and I have greatly enjoyed following the "Saga of the Server in the South.
But I am also amazed and disappointed at the actual service provided to this customer by his local HVAC companies. Pursuit of qualifications is time well spent. Smiling in North Carolina........